The United States experienced the most cyber attacks in 2008 with more than 20 million attempted attacks originating from computers within the country, according to a client study by security firm SecureWorks. China was second with 7.7 million attempted attacks emanating from computers within its borders and Brazil took third place with over 166,987 attempted attacks. South Korea, Poland, Japan, and Russia were also high on the list.

"This should be a warning to organizations and personal computer users that, not only are they putting their computers and networks at risk by not securing them, but they are actually providing these cyber criminals with a platform from which to compromise other computers," SecureWorks researcher Hunter King said in a press release. The findings illustrate the futility of simply blocking content from foreign IP addresses as a defense mechanism, added Don Jackson, the firm's threat intelligence director.

The Georgia/Russia cyber conflict was a good example, SecureWorks said. Many Georgian IT staffers thought that by blocking Russian IP addresses they would be able to protect their networks but the Russian attacks were actually launched from IP addresses in Turkey and the United States.